==Phrack Inc.==
Volume Two, Issue 21, File 6 of 11
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<> Organizations Supporting The Telecommunications Network Operations <>
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<> NETWORK MANAGEMENT CENTER <>
<> _____________________________________________________ <>
<> | | <>
<> | A description of the Network Management Center/NMC | <>
<> | and its role in providing the best possible service | <>
<> | to the customers of the telecommunications network. | <>
<> |_____________________________________________________| <>
<> <>
<> Brought to you by <>
<> Knight Lightning & Taran King <>
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<> August 9, 1988 <>
<> <>
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Introduction To Network Management - Southwestern Bell Telephone Company
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Modern Telecommunications Networks, relying on direct customer input and common
and stored program controlled switching, are generally very reliable and have
provided the means to supply low cost telecommunication service to all who
desire it. Because these networks are designed on the probability that all
customers do not require service simultaneously, they are engineered and
equipped to provide acceptable levels of service during normal traffic load
periods. When customer demands or equipment malfunctions cause a deviation
from the engineered requirements or heavier than normal calling occurs, modern
networks can become congested and network throughput can be affected.
Network Management provides a means to improve the
performance of the network during these contingencies.
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Purpose And Objectives
~~~~~~~~~~~~~~~~~~~~~~
The Network Management Centers purpose is to provide the constant surveillance
and control activities necessary to maintain the network at its optimum level
of performance. This includes the Bell Operating Company (BOC) Intra-Lata
Networks and Inter-Exchange Facilities and Circuits.
NMC's objective is to meet customer and market needs and expectations, and at
the same time, maximize revenues derived from the provision of network service.
While the NMC cannot guarantee a certain level of service to the customer, it
can ensure the most effective use of existing network capacity in all
situations. This will result in:
- More completed calls
- Higher return on network capital investment
- Better customer service
- Protection of essential services such as 911, during abnormal network
situations
- Ensuring equal access
- Assisting in national security and emergency preparedness
The NMC has the capability to alter or change the switching network on a near
real-time basis. This is accomplished thru Network Control Actions in the
switching machines. Control messages from the NMC are acted upon by the
switching machines to either expand capacity by utilizing idle equipment and
trunks or to restrict the network by denying access to traffic that has a poor
chance of completion, thereby freeing equipment and trunks for traffic that has
a good chance of completion.
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Principles And Responsibilities Of Operations
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In accomplishing the purpose and objective of the NMC, decision on network
control actions are guided by standard principle applicable to switching
technology or network architecture. All network management control actions are
generally based upon at least one of the standard principles.
Inhibit Switching Congestion
----------------------------
Large numbers of ineffective attempts in a switching machine due to traffic
overload or equipment malfunctions can exceed the engineered capacity of the
system. If not controlled, this congestion can spread to other connected
switching systems. Network management controls are available that remove
ineffective attempts to a congested machine, inhibiting switching congestion
and preventing its spread to adjacent switching systems.
Use All Available Trunks
------------------------
The switching network is sized and equipped to accommodate the average business
day calling requirements. Focused overloads (storms, holidays, floods, and
civil disturbances) can often result in greatly increased calling patterns for
which the network is not designed. This aberration can also be caused by
facility failures and switching system outages. In these cases some trunk
groups are greatly overloaded while others may be virtually idle. Network
management reroutes can be activated in many of these cases to use temporary
idle capacity in the network, thereby completing calls that would otherwise be
blocked.
Keep All Trunks Filled With Messages
------------------------------------
A message is a completed call. Since the network is normally trunk limited, it
is important to optimize the ratio of messages (revenue) to non-messages (non
revenue producing) on any trunk group. When unusual or abnormal conditions
occur in the network that cause increased short holding time calls (non-message
such as busy tone, reorder tone, recorded announcement, and high-and-dry - dead
air), the number of carried messages decreases because non-message traffic is
occupying a larger percentage of system capacity. Network management controls
are designed to reduce non-message traffic and allow more calls to complete.
This results in higher customer satisfaction and increased revenue for the
industry.
Give Priority To Single-Link Connections
----------------------------------------
In networks designed to automatically alternate route calls, the most efficient
use of available trunking occurs when traffic loads are at (or below) normal
engineered values. When the engineered traffic load is exceeded, more calls
alternate route and therefore are required to use more than one trunk in order
to complete a call. During overload situations, the use of more than one trunk
to complete a call occurs more often and the possibility of a multilink call
blocking other call attempts is greatly increased. Thus, in some cases, it
becomes necessary to use network management controls to limit alternate routing
in order to give first routed traffic a reasonable chance to complete more
calls on the network than would otherwise be completed.
The responsibility of the Network Management Center is far-reaching, affecting
many work groups and organizations both in Southwestern Bell Telephone Company,
other telephone companies, and the customers.
The NMC provides:
- Real-time surveillance and control of the switching network
- Identifying abnormal network situations
- A centralized point for information to higher management, IC's,
Independent Companies, and other BOC's.
- A focal point for national security and emergency preparedness concerns
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The System -- A Picture
~~~~~~~~~~~~~~~~~~~~~~~
The Network Management System consists of three major components: The
switching network itself, the data gathering support system, and the
surveillance and control system (NMC).
The NMC is driven by customer actions in the switching network which are
recorded and displayed via the EADAS/NM (Engineering Administration Data
Acquisition System for Network Management). Network management control actions
are directed from the CRT to the switching network via the same system.
Diagram;
Switching Data Gathering NMC Surveillance
Network System and Control
____________ __________________ ______________________
/ \ / \ / \
____________ ___ _______________
| |_______________________| | | |
| Access | | E | /| Display Board |
| Tandem | ___ | A | / |_______________|
| | | |__________| D | /
| End Office |________| E | Data | A |/
| | | A |__________| S |\
| Equal | | D | Network | / | \
| Access | | A | Controls | N | \
| End Office | | S |__________| M | \
|____________| |___| | | \ __________________
| | | \ | |
_|_ | | \| Cathode Ray Tube |
/ \ | | |__________________|
\___/ |___|
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Introducing: The Southwestern Bell Telephone Company
Network Management Centers
___________________
| |
___| Southwestern Bell |__________________________________________
| | Corporations | | | |
| |___________________| ______|_______ ______|_______ ______|_______
| | || || |
| | SW Bell || SW Bell || SW Bell |
| |Mobile Systems|| Telecom || Publications |
| |______________||______________||______________|
__|________________
| |
| Southwestern Bell |
| Telephone |
|___________________|
|
|----> Little Rock NMC Arkansas (Non EADAS/NM) (501)373-5126
|----> St. Louis NMC Missouri & Kansas (314)658-6044
|----> Oklahoma City NMC Oklahoma (405)278-5511 *
|----> Dallas NMC North Texas (214)464-2164
|----> Houston NMC South Texas (713)850-5662 *
* - After hours, this number goes to a beeper,
at the tone, dial in your telephone number.
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Summary
~~~~~~~
Network Management is the term used to describe a variety of activities
associated with improving network traffic flow and customer service when
abnormal conditions (unusual traffic patterns or equipment failures) may have
resulted in a congested inefficient network. These activities include the
application of network controls when and where necessary and planning the means
by which the impact of network overloads can be minimized.
Network Management is based upon the use of near real-time trunk group and
switching system data and the ability to implement appropriate network controls
thru the use of EADAS/NM.
Network Management is concerned with completing as many calls as possible
within the Intra-Lata network and providing equal treatment for the traffic
flow to and from all inter-exchange carriers.
"The Future Is Forever"
_______________________________________________________________________________